Based on a test set up with a 90° bend on a ¼” [6mm] radius, the Polyimide based sensors will complete > 30 million cycles and Polyester based sensors will complete >10 million cycles.
The standard Bend Sensor will function constantly between 100°C and -40°C. With some modifications we are able to get to 200°C and to -60°C
This depends on the circuit used to read the sensor. We have used 12, 5 and ~3VDC in designs we have developed.
Change in resistance is a function of bend radius and angular deflection. The sensor will also change if stretched linearly. Changes greater than 100X are possible.
The sensors have been soaked in gasoline, diesel fuel, DOT3 brake fluid, antifreeze, alcohol, motor oil, and colas without detrimental effects on the sensor. Solvents like acetone and methyl ethyl ketone will dissolve some of the inks and destroy the sensor.
The sensor is basically a variable resistor. Typically it only has two leads. In a microprocessor based circuit the sensor is set up in a voltage divider and the change in voltage is read by the processor using an ADC. There are some processors that have an integrated current DAC to bias the sensor with a constant current. The voltage across the sensor is then measured using the microprocessor’s ADC.
Under controlled circumstances it is about +/-3%
Humidity will affect the sensor. It is very repeatable and predictable. Flexpoint has a patent issued based on using the sensor as a humidity indicator.
The bend radius is limited by the material the sensor is printed on. Once the elastic limits of the substrate are exceeded then the sensor is damaged.
FSRs are multiple layers that interact with one another. The resting resistance is generally quite high if not open and when the layers are compressed together the resistance decreases. The Bend Sensor is a single layer construction. It starts at a relatively low resistance when flat and increases as it is bent.
Piezo Sensors typically will give a voltage output when it is bent. Once motionless the sensor gives no feed back until it is moved again. The Bend Sensor will hold its higher resistance value when bent and return to the lower resistance value when returned to its flat state
Yes, we have a bi-directional version that uses sensor material on both sides and has a three pin connection. This sensor will give you the resistance change in each direction independently.
Yes and each section can be individually monitored. This is a custom sensor.
Currently we print sensors on Polyester and Polyimide (Kapton) materials.
The minimum length is about .25” [6mm] plus the connector. The maximum length is equipment limited to 30” [760mm]. The width limitations are about .10” [2.54mm]
To arrange for a custom sensor please contact Flexpoint directly. You can then discuss your application and sensor design to fit your requirements. If necessary NDAs can be signed in advance.